Spinal surgery involves many challenges as the long-term health and mobility of the patient often depends on the surgeon's technique and precision. One type of spinal surgery involves the removal of the natural disc tissue that is located between adjacent vertebral bodies. Procedures are known in which the natural, damaged disc tissue is replaced with an interbody cage or fusion device, or with an artificial disc prosthesis.
The insertion of a fusion device or an artificial disc prosthesis in the intervertebral space presents the surgeon with several challenges. For example, the adjacent vertebral bodies collapse upon each other once the natural disc tissue is removed. These bodies must be separated to an extent sufficient to enable the placement of the prosthesis. However, if the vertebral bodies are separated, or distracted, beyond a certain degree, further injury can occur. Also, the disc prosthesis must be precisely positioned between the adjacent vertebral bodies. Over-insertion or under-insertion of the prosthesis can lead to pain, postural problems, and/or limited mobility or freedom of movement.
As a further complication, some implants include a series of bone-engaging protrusions (e.g., teeth) extending from both the superior and inferior surfaces, which are intended to engage a corresponding vertebral endplate of adjacent vertebrae to enhance fixation of the implant. While assisting in securely positioning the implant, such protrusions can complicate delivery due to premature engagement during delivery as the protrusions typically engage the corresponding vertebral endplates before the implant has reached the desired location.
As such, there is a need for a device and method to facilitate the proper and convenient insertion of an implant between adjacent vertebral bodies while minimizing the risk of further injury to the patient.